In this proposal we respond to the call by the National Institute of Environmental Health Sciences (NIEHS) in the PHS 2007-2 Omnibus Solicitation for "new products/devices, tools, assays to improve our ability to precisely measure environmental exposures to individuals with high temporal and spatial resolution." According to the solicitation, the device should be of appropriate scale to be field deployable and/or wearable. Ozone, formed in photochemical air pollution, has well documented adverse effects on human health, including reduction of lung function and aggravation of preexisting respiratory disease such as asthma. Emergency department visits, daily hospital admissions and mortality increase during episodes of high ozone concentration. A Personal Ozone Monitor (POM) is required for environmental health studies of the physiological effects of ozone and for validating computer models of human exposure such as the Air Pollution Exposure (APEX) model used by the Environmental Protection Agency to assist in establishing national air quality standards. We propose to develop a small (4 x 3 x 1 inch), light weight (d 1 lb), low power (d 3 watts), low cost (d $800 in parts) battery-operated POM based on the well established method of UV absorbance. The instrument will result from further miniaturization of a backpack-sized instrument already commercialized by 2B Technologies and successfully tested as a personal exposure monitor. The pocket-sized POM will have a precision and accuracy of better than 2 ppb and make new measurements every 10 s. The instrument will have an internal data logger and USB computer interface for downloading data into a personal computer. During Phase I, we will evaluate and select miniaturized components, design and construct a prototype POM, test the prototype for effects of orientation, vibration and rapid temperature and humidity change, and, finally, characterize the instrument with respect to the analytical figures of merit of linearity, precision and accuracy. PUBLIC HEALTH RELEVANCE: A pocket-sized, battery powered Personal Ozone Monitor (POM) will be developed and tested. The POM, which will be based on the well established method of UV absorbance, will facilitate physiological studies of the adverse effects of ozone, formed in air pollution, on human health. [unreadable] [unreadable] [unreadable]